I read about this somewhere (probably on these boards) and have been trying it lately. It really does extend the life of the strings! I'm currently using RIP control in the mains with Cyber Blue cross and there is no sign of fraying on the RIP after about 10-12 hours play. I hit the ball pretty hard with a decent amount of TS. Normally RIP would be starting to fray by this time (which means it is going to die soon), I have always used it as a cross before so it's even more impressive that it is holding up in the mains. One other thing I was starting to get some string movement so I sprayed them again and now there's no movement (or rather they are sliding back into position) If you use a multi give it a go.