no, the toothpaste is too thick for paintbrushes. You want the paste on a little bit thick; you want to be able to scratch it off later.
Toothpaste can also be used as masking for the edges of masking tape. It really helps assure a sharp edge.
It's really easy to do.
here's the steps:
1: paint silver
2: apply toothpaste
3: apply color coat of your preference
4: lightly scratch off toothpaste
5: wipe off surface of helmet with a paper towel to assure no remaining toothpaste
6: be wowed by your Papeesheewoosh work!
the idea is that once you scratch off the paste, you'll expose the silver underneath.
I also grab some steel wool and rub it all over the surface to get some metallic particles on the green paint, resulting in a more metallic look. make sure to get some very fine steel wool.
after getting some metal dust all over it, do a clearcoat.
blackwash the whole thing with some very watered-down paint, rub the paint off.
grab the steel wool again, but lightly dip it in some silver acrylic. Wipe off a little excess silver paint on the wool with a paper towel, then lightly rub the wool onto the helmet. be sure to do fast strokes for a better effect. this is a version of dry-brushing, I just like the result a little bit better.
I also do some black steel wool dry-brushing, it adds a nice affect.
Hope this helps!!
Also, you know what's amazing? My browser now has an auto-correct for Papeesheewoosh. LOL!!! I'm laughing my butt off now!!