Jerry became most well know for his charity for kids "Jerry's Kids" and the Jerry Lewis Telethon. I'm not sure how involved Dean Martin was with the charity, or if he was at all.
I actually helped with one of those telethons back around 1988. I was one of the people that sit and answer the phones for pledges on the stage while the TV MCs walk and talk and ask for money. It was on the local TV station in Grand Forks, ND. I never saw any "famous" people...I don't think they wanted to be in ND. Neither did I.
Aloha.