You may not have to mod the trainers if you get the right sort of ones...
The idea was accidently stumbled upon by Q who originally thought he got a good deal on e-bay £6 for converse hi tops. Turned out they were kids size 11!
But when he started to make conventional tyre sox, cutting thru tyre, he broke the blade, which went spinning past his head, so he thought, sod that! And tried the trainers, more in hope than expectation.
But he found the canvas stretched and really gripped the hoof OK. Since then he has tried adult trainers, but found then horribly 'squidgy'. The thin kiddy converse one is right, needs to be hi top or slip off.