what is the best etchant for Haynes 188 (Cobalt base)? i used:

1)HCl 37% + H2O2

2)solution A: 7ml HCl+15ml H2SO4+15ml HF+ 15ml HNO3 + 10ml H2O

solution B: 20ml of solution A + 10ml HF+ 20ml HCl+ 1gr CuCl2.2H2O2

3)HCl+ HNO3

but the result was not very good. please help me. Thank you all