Not alternating hands while jelqing

I basically jelq with only my right hand, I try to incorporate the left in but I just can’t do it right. Is it bad to only use one hand? Will it cause my penis to be non symmetrical?

I would think it could cause some curvature depending on grip pressure. Have you tried standard and reverse “ok” grip with your left hand? Do you use just standard “ok” with right or standard and reverse?