The best detergent I swear by and use (and clean whole bike with diluted) is CT18. Using a good slurp in WARM not Hot water rinsing it through is done in five minutes max, rinsing in fresh water. I have used the mineral turps and solvent method before, but eventually ruins the filter. Note hot water lets the glue let go.
To dry, I use a couple of sheets of newspaper and squeeze and squash filter between to absorb the water, time taken is about the same as forced air drying. May have to change sheets over several times.
Applying oil, I used the bottled filter oil, get a plastic freezer bag or nappy bag, or shopping fruit selection bag, pour in a palmful in it, roll around the oil to the sides, invert the bag and dab the now oily sides of the bag only to the surface of the incoming airflow side of the filter (may have to invert the filter inside out). My have to add more oil if not covered properly repeat this step (invert bag). Then just squeeze the filter to even up the applied oil. This is enough oil actually, too much make the engine run rich etc. Hands are free and relatively clean to fit filter etc.
One more step I do is grease the outer sealing edge, just for a bit better sealing.
