Welcome to the forum!
Very nice stitch pattern and dishcloth.
Did you bind off after row 2 and which bind off did you use?
It may be that a looser bind off will give you more of a wavy edge. It won’t be precisely the mirror of the cast on edge but it will continue the wave of the pattern.
One way to make a looser bind off is to use a needle 1-2 sizes larger in the right hand. Another is a stretchy bind off like this one which puts more yarn into the bind off sts.
To truly mirror the cast on edge, you would cast on for 2 dishcloths, work them to a halfway point and then graft together.