No, .22 shotshells are an extremely *bad* idea for HD, first, the shot pellets are *tiny* (these shells are sometimes referred to as "snakeshot"), they're too small to use even on game birds, a single BB pellet from a BB gun is bigger than snakeshot
Secondly, these shells would not be even close to being able to penetrate the FBI mandated 12" of ballistic gel, and that would be just on bare flesh, add some clothing, and you have practically no penetration ability, they would create a raw, shallow, painful wound, potentially angering the assailant
If you're limited to the .22LR, load up with a good hollow point .22LR like the CCI Velocitor