Several times. Original grips were perished and tearing from the gear cables pulling outwards (now secured with cable ties). One replacement grip got damaged in a crash, another got cut while loading the bike on/off a train.
As a butterfly bar user, I already had a couple of lengths of this lying around:
Buy Soft grips - one-piece - online Cut to length (BIG kitchen scissors recommended for a clean cut) making it a little bit longer than you think it needs to be (it's no problem if the foam is slightly in compression lengthwise, and it bugs me if there's a slight gap under the shifter) , lube up the grip and bar thoroughly with isopropyl alcohol (other lubricants are available) and slide on. An absolute doddle if you're replacing the gear cables and can remove the bar-end shifters (assuming your StreetMachine has them), a little bit trickier if you're sliding it over the shifter as well, but it will go. Leave it for an hour or so for the alcohol to evaporate, and job's a good'un.
A 1m length of that will do at least 4 grips worth, probably 5.
