Ditto re the K&N slab filter on my Roadster. Cleaned MAF sensor twice now always catching the drips of dedicated cleaner onto white tissue. Absolutely clear though as was our Mini's. I guess there is an opportunity to over oil the element but the instructions clearly say just enough of the red oil to show as a uniform covering on the filter material after washing it.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone