who uses them when tube fishing ?

I do. I use a small Owner crane style swivel, tied about 15" above the tube. No down side that I can see. Works for me.

If I am tubing on a bait caster, no swivel with a 3/16 slip sinker.  If on a spinning rod like a fluke, line from reel, tiny swivel,18"  line to hook with a 3/16 slip sinker..

I use barrel swivels all the time on my spinning rods just to help stop problems with line twist. I use about a 2' leader then tie on my hook and soft plastic.

Thanks everyone.

I use them all the time without problems. I am paralyzed in my right hand and my left has limited mobility. Ttying a knot using the left and my mouth is very hard so swivels are great even for tubes.

2 hours ago, collards said:

I use them all the time without problems. I am paralyzed in my right hand and my left has limited mobility. Ttying a knot using the left and my mouth is very hard so swivels are great even for tubes.

Don’t you have to tie three knots when using a swivel? Two to the swivel and one more on the lure? Seems it would be even harder unless you are talking about a snap swivel. Many guys use the term swivel when talking about a snap swivel. 

17 hours ago, Scott F said:

Don’t you have to tie three knots when using a swivel? Two to the swivel and one more on the lure? Seems it would be even harder unless you are talking about a snap swivel. Many guys use the term swivel when talking about a snap swivel. 

snap - one tie. I can use my hand and my mouth, but sometimes my wife.