It's the paste that looks dodgy. If it were just water being sprayed, it wouldn't be so bad. It's warm out there; getting soaked actually sounds nice. You'd jump straight in.
But the paste is weird. It's hard to tell what's in it, whether it's a gloopy mixture of chalk and water or something else that's going to seriously ruin your clothes. Actually, whatever it is, it's going to seriously ruin your clothes.
Everyone walking past on the street is caked in the stuff. Their faces are like tribal masks, pale and ghoulish, streaked with rivulets of the water being shot at them from the guns cradled in people's arms. It's all over their clothes, slapped across T-shirts and shorts, with hand prints like cave paintings and streaks like kids' sketches.
You can see the culprits, grinning Thai guys and girls, their eyes on the crowd looking for victims, their hands dipped in plastic buckets, swirling the gloop around, ready to pounce. No one much cares about these attacks, though; they're all taking it with smiling good grace.
It's mid-afternoon and the crowd is starting to swell as people pour into the area, ready to continue celebrations that have been going on for days.
The shops have closed. Some have boarded their windows, while others have erected small fences around their facade. The bars are starting to crank up, with Westerners perched at the metal tables drinking cold Chang in the hot sun.
Stalls have been erected by the road to cater to the revellers, selling festival essentials: cheap cans of beer, huge plastic water pistols. And water.
My hotel sits right on Rambuttri Road, which by good or bad fortune turns out to be one of Bangkok's main thoroughfares for young people celebrating Songkran, the Thai New Year. The festival is a Buddhist tradition that has morphed into a huge water fight. Nice. The chalky paste is used by monks to mark those who have been blessed, but today it's been harnessed by the young and the crazy.
A metal fence separates my hotel from the street, and there seems to be an unspoken rule that people standing behind the fence are spectating, not taking part. Only the occasional jet of water arcs through the humid air and into our safe haven. No paste.
A few of us are in this little holding pen, watching the rapidly filling street and trying to decide what to do. Get involved with this craziness, or go back inside? Run the pasty gauntlet or retire to airconditioned comfort?
Paste or no paste, you have to take the plunge. Travel, after all, is a participation sport. And who would want to say they watched Songkran from a hotel window?
So I head up to my room, don the oldest clothes I can find, and make my way back to the holding pen. A security guard gives me a smile, opens a gap in the metal fence and ushers me into the now jam-packed street. "Good luck," he says.
Immediately, I'm caught in the surge of the sopping-wet, pasty-faced crowd. A guy standing near me is holding the business end of a broom, dipping it in water and sloshing it over people's backs.
He clocks my conspicuously dry clothes, dips the broom and hits me with it. The shock is unexpected - it's freezing! He's using refrigerated water. He's upped the ante.
Fingers brush my face. I look around. I've just been pasted. I can feel it drying on my cheek.
Splosh! Some guy has just tipped a whole bucket of water over me.
Zap, zap. I'm hit with a water pistol. Some Thai girls giggle. Another guy points a colossal gun at me and lets fly with a solid burst into my chest.
The crowd ebbs and flows, sucking me along the street, soaked, pasty, wondering who decided this was a good way to see in a new year. Even in here I feel like a spectator, so I front one of the makeshift stalls and buy a couple of cans of beer and the biggest, baddest water pistol bahts can buy. This thing's a cannon. The salesman grabs a hose and fills me up with ammo, then sends me back into the heaving throng.
Now we're talking. Water pistols, it turns out, are like vuvuzelas, those plastic horns that people blow at African football matches. They're the most annoying things in the world until you have one of your own. Then they're the best.
I start blasting away like Rambo, strafing the crowd with wave after wave of aqua amusement. People smile, then shoot me back. Someone slaps me with more paste, ruining my shirt. I squirt him in the chest. He grins, then starts laughing.
I'm sure we're both thinking the same thing: a bit of water never hurt anyone. And paste is a badge of honour.
Have you ever taken part in a festival while travelling? Were you apprehensive at first, or did you dive straight in? Share your stories below.