Unfortunately from experience, this will over numb your penis. You will feel and look like a stallion but after one hour, unless you have endurance of an olympic runner, you will be stuck.
Anyway, try one brush on the penis and just have sex after 20 minutes. Don't leave it on too long as you will last too long. Other tip is to wash it off after 20 minutes and have sex after.
Pity about the smell though.