No Toil Filter sealing concern

Chiming in on this one. I also use twin air filters and no toil with their rim grease. Have used it since 2004 in many different bikes. The oil and cleaner is awesome and there is no better way to clean an air filter (especially in the kitchen sink). I did buy their filter for this model WR250R and found it was a loose/poor fit. All other models I have purchaced for fit great. Of the 30+ dirtbikes I have owned over the years this airbox is the worst for filter fittment.

FWIW my no-toil filter has been sitting in the attic for 4 years. I never had confidence in the seal either.

I didn't think fitting the air filter back into the airbox was terrible.
I can see somebody not lining it up properly if they're not aware of what they're doing, but not too bad.

I was not a fan of how the stock filter had a loose fit over the stock filter cage.
The Twin air filter fit much better.

If you want an air filter/airbox design that makes putting the air filter back in place a pain, try a Honda CRF450X.
Do this bike a dozen times and you'll never complain again. :)

I know this tread is old but I have noticed that once you get the filter cage to line up with the metal lip on the air intake track then the cage pushes down on the filter creating a seal that is very tight. No matter what filter you use I don''t see how dust would be able to get around this seal even without rim grease.

That's true, and that's why I don't bother with any kind of filter sealing grease.

If you get it right, just the oiled filter pressed down against the sealing edge of the airbox will seal just fine and dandy.
If you don't get it right and have the foam filter slip off the filter cage while installing, or install the filter and filter cage a bit crooked, you can have a leak.

If you want to see what you are trying to achieve with where the filter cage and airbox meet, test fit the bare cage (without the foam filter) into the airbox.

This is not specific to any bike. But for 20 years i have been using belray filter oil and filter cleaner. Ridden a lot and used to race to. Not once did i have any issue with dirt ingestion on a single bike i have owned. I usually have a min of 2 filters per bike so i can install a clean one while servicing the dirty filter. I have also never had a bad filter and bought many Twin air brand name filters for many bikes. The dust level where i ride can be extreme to say the least. And group rides are so dusty. I am choking and spitting up dust for 12 hours after a ride many times.....bike was always fine.