By dirty I mean debate tactics designed to waste your time, confuse you, distract you, etc.

So Ben Shapiro?

Dirty practices are arguments that take longer to refute than present, even if ridiculous. For example arguing that the other sides arguments aren't topical or because they don't reject hierarchical power structures they lead to nuclear war which outweighs everything.

I am sure the games that work on voters but not on debate judges. One is for example avoiding the real question/topic and talking about something else entirely. Like taking about climate change when asked about education policy. Or bringing up the fact that your opponent used her sexual skills to rise up the ladder.

I expect he means ad hominem attacks instead of just debating the topics at hand.

Actually ad-homs rarely show up in competitive debate. Competitive debate has the norms that an unanswered argument is considered to be true, and that the winner of the round is usually decided by a judge trained in argumentation. (most often a former debater or coach themselves)

For competition dirtier tactics including making 'must answer or you lose' style arguments that take longer to answer than they do to make in order to generate a time advantage.