While practicing I find that my hands get very sweaty and I've damaged the Syahi on the Dayan significantly when my fourth finger rests on its outskirts. Luckily, these tabla are very old so I'm not bothered about them, but now that I've bought a new pair I don't want the same to happen again.
I can't constantly use powder to soak up the moisture, because it begins to build up on the Syahi.
Of course it cakes up, thats why you use a credit card every once and a while. The disadvantage to talcum is that it accumulates in your lungs, and over time can cause some serious issues down the road.
Beenkar Ted Ceplina