I got a kit from Amazon, UES -FFR-24, I also did a bit of research on internet, watching videos. I started using a rocket blower before using the swabs.
The instructions on the solution bottle were misleading. When you remove the top of the bottle there is a stopper. You are told to remove it. I didn't, instead I poked a whole through it with a pin so that I could dispense one drop at a time.
It took 6 swabs ( you should only use each swab once each side) but the sensor had never been cleaned before, it was very dirty.
The first two swabs still left it dirty, so I used more fluid on the third. This left smears so I used a fourth without fluid. Then found there were still one or two specks, so needed two more swabs, used as instructed with only 1-2 drops of fluid to clear them. After each swab I took another test shot to examine.