Any way to make mashed sweet potatoes less stringy?

After cooking the sweet potatoes run them through a ricer.

Whether you use a big ricer or a little ricer the process will convert the softened 'meat' of the sweet potato into a consistently sized pellet, about the size of a grain of rice, that can then be seasoned and whipped to smooth consistency. (I also add a bit of honey, butter and brown sugar...but that is approaching a 'recipe')

I peel and cook sweet potatoes with butter or oleo in a crock pot, about a half pound for 6-8 pounds of sweet potatoes, then use an electric mixer to pull out most of the strings - mix for a few minutes, lift up the mixer to spin off the sweet potatoes, turn it off and wash the strings off. Do that until only a small amount of strings are collected. Then to make it essentially string free, push the hot sweet potatoes through a good quality kitchen sieve with the back of a large spoon.

It might come down to technique.

I've had good luck with baking sweet potatoes whole (unpeeled), and then mashing them. But because I know the strands tend to run along the long axis, I cut it into sections (about 1cm / 1/2" thick) across that axis before mashing.

They're soft enough at that point that I just use a metal spatula to chop them up, and then take a potato masher to them.

And I sometimes do them as 'smashed' potatoes, and leave the skins on, which would mask any stringiness, but I scrub them well before hand, and still cut across the potato before mashing so the skin is in smaller chunks.