I know people say you can use the Han-D-Mag for tape degaussing, but it is on the weak side for tape so will take several passes. I think it should do 1/4", but any of the inexpensive Radio Shack tape erasers are stronger.
Use the back side of the Han-D-Mag (opposite the tip). Both ends are “active” on the Han-D-Mag; one side just has a tip to reach heads and small parts of a tape path. The back has a stronger field than that measured at the tip.
While holding the tape flat on your palm (or flat on a table), slowly move the degausser in a circular motion over the tape starting from the hub and working out. Hold the degausser as close to the tape as possible without touching it. It won’t hurt anything if it touches the reel, but might scuff or scratch it. I’m picky about my reels, so I put a very thin layer of felt on my degaussers. For ¼-inch tape on 7-inch reel I would make that circular pattern at least three times on each side.
Yep, I forgot to mention... treat it just like any othe degausser by turning it on a least two feet away, slowly move in and then after degaussing slowly move it away at least two feet before turning of. Also make sure you keep it away from any other tapes you don't want to erase.
Some Radio Shack stores may have some old stock, but for the most part, like everything else in the tape world we’re in eBay land… unless you want to pay big bucks for a Geneva or Nortronics, which you can still buy new.
Some specific Radio Shack models to look for are 44-210, 44-232, 44-233, 44-233A. The 44-233 is often listed as “High Power Tape Eraser.” I think the 44-233A was the latest before they discontinued them.
Below is my ebay search for bulk tape erasers. Just go to the ebay homepage and copy & paste the string into the search box.
