Do the Split moves (Guard and pain) stay in effect after the user switches out?

Question

This is for my Shuckle-Deoxys A duo for double battles. Also, I don't need to know about power split. Thanks

Answer 1

If one of the Pokemon switches out, it wears off for that specific one

So let's say Alakazam uses Guard Split on a Shuckle. If Shuckle switches out, it gets its normal defenses back. If Alakazam switches out, it goes back out its normal defenses.
EDIT: Just saw Pain Split. All HP based moves stay in effect even after a switch unless the target has Regenerator.
Source: experience

Hope this helps!

Answer 2

As far as I can tell, the effects of Guard Split wear off after a switch. However, the HP averages of Pain Split will remain after a switch.