Correcting circling rootstock roots?

I have many pear OHxF87 rootstock that have circling root systems, and need an opinion on how to proceed.
Background- Someone planted them last year in what I assume was a nursery bed. Spring bench grafts failed and summer bud grafts also failed. They dug and sold them for cheap- but there is hardly anything at all to graft onto, all cut off. The roots are alive, but definitely need to grow for a year before I try to re-graft. Roots are flexible for now, I think the stock was just shoved in the holes, definitely roots were not spread out when planted. Grafts were very low, I think they were grafted too low to take well. Cheap enough for me to try and work with them to get a lot of trees later.
My question is- how do I deal with the circling? They are much too twisted to grow a stable tree. Most are still flexible enough to correct, but too stiff to just spread out as I plant. I have debated strapping the roots to a bamboo skewer to straighten and harden, then taking that off next year when I graft them. Or I could root-prune the worst and let new roots grow. What would the best material be for tying the roots straight? I have cotton thread or string of many different types, raffia, jute twine. Very few rubber bands in the house, as I am latex allergic and get rid of them fast. I could get some if that would be better, having something somewhat stretchy. Would they break down underground?

Personally, I wouldn’t worry about it too much. I might prune them back a bit. They will go deep looking for water when they are planted in the field.

If you can trim the most tangled parts of the roots/untangle them. As long as the tangled roots are not chocking each other so to speak they should be fine

OK, I might be overthinking this for rootstock I have to grow out anyway. I will prune the worst. I did untangle, and have to trim out the crossing roots. I can see why these roots didn’t do well as they were.

if the plant is dormant you can trim the roots significantly and it will survive. its better to remove roots than leave circling roots in the long run.