Really hope it works for you GL, sending you all the poonami vibes I can! Unfortunately it didn't work for Eleanor ... always worked a treat as a newborn. The first week we were told to check her temperature at every change, and she'd poo without fail (so every 3 hours!).
We used a normal digital thermometer and just stuck it in as fas as it would comfortably go, which is further than just the tip (I was super scared doing it for the first time, and did the tip only ... got told by the midwife to not be so worried and that you get a more accurate temp when it goes in deeper). I'd say it went in about 10mm. We didn't really have to wriggle it much for it to work.
That said, I don't like doing it any more as I have since read on the internet somewhere that it shouldn't be done as it can cause problems with the muscle. Very conflicting info, told we -had- to do it by our midwives, and then read it's not ok. I wouldn't do it unnecessary, but we did try when she was constipated.
Another weird difference between countries:
In Holland everyone we've seen medically has told us to make sure we give Eleanor 5ml of Vitamin K a day, and 10ml of vitamin D. The vitamin K should be kept up for the first 3 months, the D until you stop breastfeeding. Tried to find vitamin K in England to be told you can only get it on prescription and that it's pretty much unheard of here, eh? The vitamin D can only be bought in baby multivitamins. In Holland I was also told to have a full dose of vitamin D myself until I stop breast feeding, so I guess I'll just do that until Moo is old enough and not bother with medicating her any more. She's had 2 months, and if non of the English children get it it can't be that bad to miss.