To wear my strings in, I sit bending every string up as far as I can at each fret between 5 and 17 ish, and repeat until there's no movement - it doesn't take very long really.

Fast fret will keep your strings and fretboard cleaner, which will prolong string life. I tend to just wipe the boards clean when I change the strings with a bit of water - just a little bit on a cloth... not sure if it's right, but after 20 years of playing I've yet to do any damage... I've never used solvents. I used to use lemon oil as I recall, but I ran out and used water instead with no worries...

What makes your strings break (aside from dodgy saddles etc) is sweat corroding them and the stretching making them thinner over time, and hence weaker. Strings are a consumable - they break.... buy more....