This is basically what I do for straplocks, and it works, hasn't failed me on either of my three guitars.
This is the strap pin that basically comes with EVERY guitar.
Now just unsrew it, flip it around, put the screw back through it, and line up your guitar strap with it so that when you screw it back in it will act as a strap lock.
The only downside to this is that with some guitar straps, you'll have to unscrew the strap pin if you want to adjust the strap height.
I don't have any pictures right now, but I will take some and post them ((when its not 3 AM *yaaawn*)) to show you how it will look when you reverse it and everthing.
Me being a cheap, poor, little guitarist I figured this out when I was like fourteen and wanted strap locks but then saw some for $20, and was like "no f*ckin' way"....so I improvised. 😎
