I'm not a fan of the 4 tone ACRN, did nothing but bad things for me. Everybody is different though so you really do have to experiment and see what works for you. I think that my main gripes were the ear canal earphones and the lack of variance. Being a musician the use of just 4 tones was irritating and they aren't musically tuned so feel unnatural to me.
I have notched out my tinnitus frequencies from the whole spectrum before but haven't done much with it. I didn't notice any immediate effects but didn't really persevere. The main problem with doing this is the same as with the 4 tone treatment, you need to reevaluate your tone/s reasonably frequently as things are likely to change.
yeah you're right, experimenting is the key here. Though, I still don't get why only four tones are being used for cr neuromodulation instead of multiple throughout the whole frequency spectrum (20hz-20Khz and maybe beyond)? Are the sounds you made and the ACRN different in terms of synthesis? Are they focussing on the same principle?