Back in teh day i used a simple wire wheel brush to gouge the bike frame clean before painting. It made the paint stay on SOLID and never wear off. In this case with an outdoor item you’re gonna want an ‘imperfect’ strip as the marks/ scratches will make a paint job stick.
I would not reccommend an agressive wire wheel as I over did it last time I rebuilt a bike.
The sand blaster might not be big enough. I’ve used it before to strip metal parts but they were about half the size of a bike frame.
You might consider taking one of the hand machine sanders with an aggressive grit to strip the paint job.
A chemical option might not be good as with OEM bike paint it’s going to be on solid and thick and you’re going to create a LOT of fumes trying to strip it. and then you’d have yet another step after that trying to switch from a chemical job to a sanding job which would invovle cleaning in between and drying. Since you’d have to sand it anyway to create a nice surface for the paint to stick
I’ve done a handful of bike rebuilds. good luck!