Do you mean to coat your tube? or do you mean to help you get the tire onto the rim? If the latter, then I recommend you try without any lubricant at all. Your tire bead and beat seat in the rim should be nice and clean when you install your tire. If you can't do it with the force of your hands, then keep practicing. If you still can't do it, use a plastic tire lever carefully. Lube on a tire bead will compromise your tire seating and increase your chance for a blow out.