If you're going to recommend a 22, or anything else for that matter, you need to be honest with both yourself and whoever youre recommending it to. Guns arent a talisman, regardless of the caliber, and if you arent willing to put in the hard work to be at least somewhat "realistically" proficient with it, then all you really have is hope and luck, and basically, a talisman.
The answer here isnt the gun, its whos shooting it (as with any of them). If all you can realistically handle is a 22, then your prep work (and you will have to work at it) is at the very least, the same as anything else, and you do need to put in the same amount of hard work, and understand that you may need more, especially if you choose something thats really not appropriate for the job at hand.