Can i use benzocaine on my childs penis 7yr old so that he does not feel the pain while i clean his penis?

NOT REALLY,: Use mild soap during shower, like one uses on the whole body. There is no special cleaning of penis. If uncircumcised, just retract the foreskin gently and wash with water. Moreover, why mother need to be involved in this, tell your son to do himself (as long as this is a normal child, no other issues).

Benzocaine: Yes you can use it to clean you child's penis.

Would not recommend : Benzocaine products should not be used on children (especially under age 2) except under the advice and supervision of a healthcare professional. I feel potential risks outweigh benefits. Gentle application of mild soap and warm (not hot) water or tub bath should be able to clean any penis without the need of a topical anesthetic. Avoid painful, forceful retraction of foreskin.

Yes but not needed: Benzocaine (found otc in vagisyl cream) is moderately effective in numbing the tip of the penis. Allow 5-10 min after application for best effect. It can result in redness and swelling (not usually an allergic reaction) that goes away in a few hours. General cleaning should not cause pain, however. Use baby shampoo and retract foreskin (if any) very gently. Do not rub with towel or sponge.