To clean a state’s voting rolls, the voting rolls should be closed (no new additions) right after fixed date (inauguration?) and a new empty voter roll started.
The roll should start with the state leaders, then county clerks. The rolls should be protected by distributed ledger technology (think bitcoin) and a copy of the current roll provided to each county clerk as well as to each party.
Each new entry would then require proof of citizenship and residence.
Sure, if you want a clean election, but who would want that?