I use swaps from several brands, today I have Rollei branded ones. I buy Isopropylalcohol 100% in 50ml bottles in the pharmacy (here it is about €1.-) and use it inbetween max 1-2 month. It is hygroscopic and the later embedded water will make streaks on the sensor. I use the rest for cleaning normal surfaces and always buy a new bottle when cleaning sensors. Then in one job I clean all my sensors, using a fresh swap for every touch on a sensor. I do it since 2006 on Sony, Nikon, Leica, Pentax without any problem. I have an Eyelead magnifying glass to check. I tried as well a jelly pen. Better to avoid it. It is a help if the dirt doesn't go away when you blow it out, but you sometimes get residues on the sensor that make it necessary to re-clean many time with a wet swap.