Dividend capture strategy question.

I’m looking to test a dividend capture strategy in my Roth IRA for a couple months to see if the tax protections make the strategy viable. I’m aware I’ll probably lose a percentage on ex-date sell off, but from my research I believe sticking to solid established companies and (in particular) market following ETF’s I can mitigate loss and capture a fair amount of dividend payouts. Does anyone here have experience with this strategy?

And also here’s my dumb question: If I purchase a stock the day before the ex-date can I sell on the ex-date or do I need to hold through open on the day of record to receive the payout?

Thanks all!