The wallet scrubber is used to sell currencies on your exchange that are too small to sell on their own.
How does the scrubber work? The wallet scrubber takes the leftover amount in your account (dust) and creates a limit buy order, filling that particular balance to a point the exchange accepts it as a trading pair. Afterward, the hopper will sell all the funds and leave no dust behind. This way the scrubber literally "scrubs" your wallet and only leaves your base currency!
Pick up leftovers If you enable it, this tool will run new sell orders to include leftover balance amounts to keep your balances clean.
Automatic scrubbing If enabled, your hopper will run the wallet scrubber on each hopper run.
No Open positions
When enabled, the wallet scrubber will continuously try to sell leftover balances and not leave open any positions.
Are you using Binance? When you use Binance, it is not recommended to use the wallet scrubber, but rather to convert the dust positions into BNB. The BNB can then be used for paying transaction fees.