Bent single crystals can trap and deflect particle beams, thus assisting in slow extraction or beam scraping. This technique has been applied in a vast range of energies, from 5 MeV to 900 GeV, with achieved bending angles of up to 150 mrad. In IHEP Protvino the efficiency of crystal-assisted extraction from 70-GeV accelerator has reached 65% with extracted-beam intensity of over 10^12 proton per spill of 1 s duration. We describe the progress of this technique and outline applications.