Rant: I bought a $40 'professional' lens cleaning kit and it made my sensor worse
I grabbed a lens cleaning kit off Amazon for $40 because my Canon 6D sensor had a few dust spots and I figured I'd save money over sending it in. The swabs left streaks and the blower they included actually pushed more dust around, so I ended up paying $75 at a shop in Denver to fix what I messed up. The swabs weren't even the right size for a full frame sensor and the solution had a weird film to it. Anyone else had a cheap cleaning kit backfire, and what do you actually use for sensor swabs?
Learned the same lesson the hard way with my old 7D. Bought a cheap kit on sale and the swabs were so flimsy they left tiny hairs all over the glass and the solution dried with this cloudy haze. Took it to a local shop and the guy said the pads were too small so I was basically dragging the plastic edge across the sensor. Cost me $60 to undo the mess plus the $25 I wasted on the kit. Now I only use the branded swabs made for my exact sensor size and a rocket blower for the loose stuff first. Saving a few bucks on sensor cleaning is never worth it, the sensor is way too easy to scratch.
My buddy did basically the same thing on his Sony last year and it turned into a whole ordeal. He grabbed some no name swabs off a marketplace listing because they were half price, and the first pass left streaks that looked like smeared butter across every shot. He panicked and went at it again with more pressure, which is the worst thing you can do, and ended up pushing dust into the corners where the swab could not even reach. Took it to a repair place and they told him the pad had come loose from the stick mid swipe, so he was basically rubbing bare plastic around in there. Ended up paying almost a hundred bucks for a proper wet clean plus they had to blow out the chamber. Your point about matching the swab to your exact sensor size is the big one, a full frame pad on a crop body just does not cover the edges right.