Disco 3 (LR3) Glow plug removal

Seasons greetings to all. Need to change glow plugs on 2005 TDV6. Have got to them (pain) and they are properly tight, now i have read threads about this before but my question is, who has come up with the most successful way to remove them without breakage !!! Chap down the pub mentioned freeze kits, never seen them myself but thought i would ask if anyone had used them. Cheers.

what i have heard is a 50/50 chance on any of them, main dealers hate doing them, snap 2 then ring you to tell you what is happening, 2k is the average total bill! i may be wrong? i maybe sort of right?
sort of another reason that puts me off getting a tdv6,

I've used this stuff myself on various bolts and nuts with a great success, not on glow plugs yet but IMO it should work a treat, or if this doesnt nothing would and the head of the plug will brake in which means cylinder head off job...the heads of the glow plugs used to bulge when they get old that's why the get stuck