You create a bunch of dummy contracts when gas is cheap. Then on your transaction where you're paying a 100x gas price to win the contract, you self-destruct as many contracts as you can to max the refund. However the self-destruct call itself costs gas, so you want to make the call as simple as possible. This is a pretty simple: 1) check caller address, invoke self-destruct. So you'd just write the entire contract directly in EVM byte code instead of using Solidity.
You don't have to leave solidity, it could all be done in the fallback/default function, no?
For the rest, you described gas tokens, but self destruct refunds were removed with London so they are all worthless now.
Yeah, for gas tokens you're right. This was all pre-Flashbots, so talking about February or March at the latest. Flashbots kind of wrecked the whole game. Now it's a whole lot simpler, just ship transactions to Flashbots and bid as close as possible to breakeven. Consequently 90%+ of the profits now go to the miners.
