I never did, but if you want to try, you can boil sorbent in 0.1 hydrochloric acid or treat by potassium dichromate in sulfuric acid (it must completely destroy the DNA).

P.S. All these methods lead to particle hydrolysis sorbent.

Instead of regeneration you might want to consider using 10x less beads (again in the same high salt, PEG buffer). I am not particularly familiar with these beads, however Ampure beads have huge excess binding capacity.

If you must regenerate beads, I would opt for HCl (50mM or even 25mM )