Yes, please share if you can! From my knowledge, utilizing the philtrum doesn't change anything physiologically and just stimulates the recipient to breathe (which would help if you're battling a dive response). I've successfully used it in apneic anesthetized birds and actually just talked about it with a zoo med clinician in the context of speeding up reptile anesthesia induction/recovery. Would be cool to know if there is evidence out there that it actually changes shunting.
I've never tried the philtrum in a turtle/tortoise mysef, I've always induced with propofol IV/IO (I've seen it done with the subcarapacial sinus and done it once myself, but you need to be confident in your stick and some people don't like inducing with the sinus) and maintained on gas. Never needed to stimulate breathing since you have to manually ventilate a chelonian the entire time it's fully anesthetized anyways.
I geek out over reptiles and I really like anesthesia