my boy did this and had some good affect but it didnt get all the resin out, and it stank up his kitchen worse than boiling regular buds would,also it seemed to make the glass a lot more fragile afterward and the glass felt different too, almost sticky. his pipe broke a couple weeks later cuz he dropped it so i dont know if cuz it was boiled or not it made it more fragil but that seems to be the case, cuz it dropped on carpet and not from that high and it was just a clean break not a shatter. the boil method works but it stinks up the whole kitchen and weakens the glass
if you want to clean your resin out though you can get regular rubbing alcohal and iodized salt, or crushed up rock salt (i think the rocksalt works better) and mix a good amount of the salt and alcohal together in a zip lock bag filled about 1/3 of the way. give it a good shake. next drop your pipe in there and make sure your salt gets into the pipe itself. shake it up real good and make sure theres lots of friction goin on in your pipe. the liquid in the bag will turn a real dark color then the completly black and will smell horrrible but your pipe will be nice in clean, there still may be some chunks of resin in there but you can get those out with the strategic use of paperclips and q-tips. also if you just take a paper towel and wrap it around you finger and rub the inside of the bowl area (where the weed sits in the pipe) anything left in there should come right out as well, if it dosnt then you might have to give it another soak in the liquid
hope that helps you clean your pipe
make sure you wash out your pipe with regular water real well before you smoke with it again