I did ours at the weekend. I have to say that wd40 helped. I eased the edges of the sealant away with a sharp scraper, then sprayed with wd and left it for a few minutes. the treated sealant came away more easily. You still have to hack away at the main bits, but it seems to soften/dissolve the sealant enough to make a rotten job a bit more bearable.
It also made the cleaning much easier: another spray then removing the traces of old sealant with a cloth/scourer was easy.