I have to agree with you that the duct tape method has alot of followers on other sites around the web. My wife is in the process now of finishing off some nasty planters warts that she had on her feet for years. Very painful and very hard to get rid of...until now. Slight variation on the method is to use sulfur powder (very cheap and found in drug stores etc..) as well as duct tape on the warts. Some people recommend sulfur soap (never tried it because I couldn't find any in my area).
Like you said wash your feet, dry well. Apply sulfur powder to wart and cover with duct tape for as long as it stays on. Repeat process until the warts are gone. 1 - 4 weeks depending. Have fun!