I was just recently told it is better to do this...With what kinds of chocolate? Melted?
I have just melted Merkins chocolate then painted it on the krispies, it gives a smoother appearance once covered in fondant. I did this for the donkey cake in my photos.
I use candy melts. They dry hard and keep the RKT from changing shape from heat or shape.
I used candy melts as well and a clean paint brush to paint it on. I then just used the heat of my hand to smooth it after. Worked great on my Mickey head that I did recently.