It’s been awhile, so I can’t remember exactly how it worked (I’ve used an accountant for the last 30 years or so), but I was able to argue that it went to benefit my day job (which it actually did), and I mixed in a lot of stuff that directly benefited my day job (like taking my team out for a holiday dinner, on my personal expense, as the company didn’t do that kind of thing).

I wouldn’t do it without a decent accountant. In my experience, they always paid for themselves.