AWESOME STORY! YOU ARE A TRUE HERO! And as far as the mouth-to-mouth...here's our story(ies).
We had a bearded dragon, Alice, who was missing half left front arm, most fingers from right hand (the normally longest finger was stumped and the only one left - you know it looked like she was "filppin' the bird" all the time), missing foot from right back leg, missing toes from back left leg, stumped tail, and later in life became paralized due to growth on spine. She had been chewed on by siblings when they hatched (bad caretakers at the pet store). She could still get around very well; handicapable she was. We had a shallow 1 inch deep water dish that we only filled half way; it barely crested the top of her body. One day when Scott came home from work he found her upsidedown in the water, not moving. OH NOOOO!!! He grabbed her out, held her vertical and squeezed the water out; then started mouth-to-mouth. SHE SURVIVED! This happened again 2 months later and again she survived! After that, we put a smaller dish in that she could not get into for bath but only drink. I don't know why this happened. She had this same water dish for 2 years and never a problem until then. A friend suggested she was trying to suicide. ?? She passed away several years later, not due to drowning, but natural causes.
We had 2 savanah monitors, one slightly smaller than the other. The girls lived together for about a year, no problem. One day my nephew came running outside yelling ISABELLE IS EATING RUTH! We ran in and found Iz sitting on Ruth with her head in her mouth with Ruth's head twisted all the way around. I picked up Iz and Scott pried her mouth open and pulled Ruth out. He quickly took her to the other room and shook her and massaged her; no response. He started mouth-to-mouth (remembering the episode with Alice) and SHE STARTED BREATHING AGAIN! I don't know that this was a good thing, she had brain damage and never ate on her own again. We had to get her started on the mouse and then she would swallow. She did drink on her own and roamed the house as she normally did before. She lived for many years and died of old age.
Mouth-to-mouth on a chick or a lizard... YUCKY? I think it is worth it and would do it myself if needed by any animal.