@CXRAndy wouldn't it be less messy to seal the tyre first then deflate, remove valve core and insert sealant, insert valve core and inflate?
Yes thats the other method, I use the former only because i've got a method where i dont spill the sealant. The method you suggest works just as well, only it takes a little while to put sealant into tyre. DONT SCRIMP ON THE AMOUNT OF SEALANT 75MIL/TYRE