Hi Ric - The recommended dosing and application is to apply 5 mg once nightly to clean, dry area on the back, abdomen, upper arms, or thighs (do not apply to scrotum).
The problem with applying it to the scrotum is the the absorption is greater and the testosterone levels can become toxic. This can effect the liver and other organs. Also the extra testosterone can be converted into estrogen which can cause impotence and gynecomastia ( breast development) which may be very unpleasant.
In one study the absorption was shown to be five-fold greater so a much lesser amount is required . The problem is that unless your monitoring you testosterone levels it could be unsafe. However, you can discuss this with your doctor if you are interested in the mode of application.
Jordan WP Jr. Allergy and topical irritation associated with transdermal
testosterone administration: a comparison of scrotal
and nonscrotal transdermal systems. American Journal of Contact
Dermatitis 1997 8 108-113.