Can be fashioned from three wooden tongue depressors, the smaller, thick ones work best. Can be found in craft stores in the wood aisle.
Cut the end of one to server as a spacer and glue together.
Hold the body of the device and pull towards yourself. Rotate and repeat.
Made and used these thirty plus years ago where we made military and very high end precision resistors. After burn-in and whatever else the parts needed, this is how they straightened the leads prior to shipment. Works well for tinned and gold plated leads without damaging the finish. It will also remove any oxide layer if they're old, pre-lead free leads.
