小林製薬の香るかんたん洗浄丸 ピーチの香り パイプ洗浄剤 ( 12錠 )/ かんたん洗浄丸 1 各

This didn’t work at all. Just a little bubbling, but no improvement in the drain.

This works pretty well

It smells good. The smell is not too strong to trigger my migraines. It's a bit pricey though.