An easy way to clean the magnetic read / write heads on a 3.5″ floppy drive is to use a trumouse cleaning disk
The disk can be used dry or wet, to use wet just add a couple of drops of isopopyl alchohol to the white disk material before inserting into the drive
Below are download link for Amiga, Atari ST and PC DOS software that will work with the cleaning disk
Floppy Drive Head Cleaning Software Download
Amiga Floppy Drive Head Cleaning Software
Atari ST Floppy Drive Head Cleaning Utility
DOS DISK DRIVE CLEANING UTILITIES
The DOS cleaning utilities are for vintage systems that run MS DOS, the .ZIP archive contains two drive cleaning tools Cleaner.exe and Floppy Disk Scrubber.com
typing Cleaner.exe into the DOS command line will start the drive cleaning program
To run floppy disk scrubber you need to type flopscrb.com followed by the disk drive letter A or B and then the amount of seconds you want to clean the disk, example commands below cleans drive A: for 25 seconds
“flopscrb.com a 25”
Screenshot of Cleaner.exe – PC drive cleaning software