send in the original bottle if you'd like, but the sample size bottles are what most use. I personally like to tape the lid to the bottle with electrical tape, then stuff it in a zip lock bag padded with paper towels. (to stop any leaks), then throw in a box padded with whatever, newspaper, styrofoam peanuts, real peanuts, popcorn, nut the buttered kind, MF towels, 100 dollar bills, leaves, etc.......