Petrol & other solvent types actually expand the foam so holes that might have been 2 microns now are 4 or larger and risk letting dust through. Although if sufficiently oil they should still work alright but is it worth the risk?
There are some great products out there, and expensive, but I find 2 to 3 times through the mineral turps bath does the trick. I reuse old baths for the first wash as this is to dislodge the bigger stuff using fresh for last. I have spare filters so if the filter is muddy I use another so I can properly clean it. First with turps then with detergent, dry then through the turps again.
I dry with a heat gun and oil with Motul in a large ice cream container. Tipping unused oil back into the original container.
I use spray on oil to spray around the air box & covers, you would be amazed how much dirt this traps stopping it getting to your filter and inside the manifold throat, before carby, to catch any nasties that get passed. I do this so that when I remove the filter I look inside and have yet to find anything but if I do I know I have a sealing problem. I also grease around the sealing surface of the filter.
If I have been for a short ride or practice with little or no dust I just check the filter and if it looks good I give it a light spray with the can stuff but let it dry, tacky, before starting. ALWAYS clean a filter after pressure washing & never start it till you do. Water can pool on the filter and, if sufficient in size, will suck in as a blob taking contaminants with it. I destroyed a new motor in less than 20 seconds starting it after washing.
Hope this helps.
Viper666