Sometimes, on rare occasion, the new-school techniques just aren't all they were made out to be. I've heard all kinds of wild methods for removing fishing line memory from spinning reels and have probably tried most of them. Some of them are okay and work a little, but nothing beats an old trick my dad taught me when I was a kid.
It's easy and it works like a charm. Check this out.
Remove the spool from your reel
Yes, you'll have to cut your lure off for this one. But it'll be worth it. Cut your line, wind any slack line onto your spool and use the line clip on the side of the spool to secure your tag end. Once all of the line is secured, unscrew the spool from the body of the reel.
Just add water
Take the spool you just removed into your kitchen and run some very warm water over the line for a minute or two. Rotate the spool to make sure all of the line is getting some direct contact from the water.
Heating the line like this will remove nearly all of your memory. This means a drastic reduction in wind knots, kinks, line twist and any other type of line management issue. In addition, you'll enjoy much longer casts than before. Whether you're casting overhead or skipping a bait underneath overhanging cover, the difference is certainly noticeable.
Condition to make it last even longer
Now, this part wasn't in my dad's original lesson over 20 years ago. But heck, technology and research has come a long way since then. After you're done running water over the spool, I strongly suggest spraying some type of line conditioner on your line before re-rigging everything. In my opinion, this helps your line stay limp longer.
It's important to note, however, that I do not use aerosal line conditioners. I've had some bad experiences with it over the years in regards to line failure. My two personal favorites are Reelsnot and Kevin VanDam's Line and Lure Conditioner. Both are very good, but Reelsnot is certainly slicker.
Do this before every full fishing day
When I was young, I fished as a co-angler in a few tournament trails and I would carry several extra spools of line with me because I could never trust the line on my spinning reels. I was terrified of being down a reel or two in the middle of a tournament just because of a random blowup or wind knot. It happened twice and I vowed to never let it happen again.
This trick I described is the cure to all of those worries. But if you're going on a long fishing trip and spinning gear is expected to be a part of your arsenal, take a few minutes and do this the night before you hit the water. It will put your mind at ease and result in much longer and more accurate casts.
Hope this helps!