What is the correct way to use certain dry? Some say they apply it every 3-4 days, and others say certain dry have stop working for them (these people apply it everyday). For the people who apply it every 3-4 days, what deodorant do you use during the 3-4 days?
Im just looking for the correct directions for this product before I buy it, so if you can help me I will be greatly thankful!

Certain Dry isn't a deodorant, it's a powerful Antiperspirant. SO that means that you should be wearing deodorant to mask icky smells while wearing Certain Dry. I used it a few years back. I had really really bad sweating issues. I used it once a day with deodorant for 3 months, and my problem disappeared!

P.S. Do NOT put it on immediately after shaving underarms, it will BURN!