Just to clarify with burns: I don't just go about throwing burn gel on everything. If it's a powder, we brush it off, and then we irrigate as appropriate. Burn gel comes after.
I personally have two ADC scopes I payed $20 a piece for. They work great, and I can hear everything I need to. Interestingly enough, I can't hear anything when I use the Littman scopes we carry on the bus.
If you are NY EMS provider there is a guide to writing PCR's in the Blue Book they gave you in EMT class. You can use that as a reference/ starting point.
Having said that, practice makes better. (not perfect :) )
I've always been told that as far as irrigation goes saline and sterile water are essentially interchangeable. I've used both with no complaints from patients, but only for smaller lacerations. As for burns, we use Water Jel. The hospital also uses it.
Here in NY we are allowed to use them, but I don't recall it being covered in EMT class. We also have Rad 57's for CO alarms and FF rehab. (They also have a pulse ox function.) I find them useful and highly accurate. They are especially helpful when you are treating more than one patient...