If you are rubbing i.p.a. into detail with a cotton bud, kitchen towel or cloth then fibres will get caught up on that detail.
ipa is what our American cousins call rubbing alcohol and stands for Isopropyl Alcohol. You can get it off Amazon and if you buy it in larger quantities, it is very cheap. It is good for cleaning brushes and air-brushes of acrylic paint. If you do buy a large quantity then be careful of storage as it is flamable (I buy boxes of 5 x 1 litre bottles at a time as it is easier to dispense than larger containers)
Among the uses I put it to:
...Cleaning parts pre-painting as mentioned
...Rinsing through the
airbrush for colour changes (I use MRP solvent based acrylic) it suppliments using more expensive thinner/Mr Tool Cleaner
...Washing brushes that I have used with Vallejo water based paint
...Liquid seam sanding. This is a good option for removing surplus filler when you have filled a seam and want to avoid losing detail with ordinary sanding. Vallejo Plastic Putty or the Gunze fillers, Mr Disolved Putty and Mr Surfacer work well with this. You do have to rub hard with the cotton bud and let the ipa soak the filler a bit in the process.