Just from reading the instructions, they are likely different. If I follow Ilford's washing instructions but using Perma wash, will my prints be washed sufficiently of fixer? I'm guessing likely not, but in case someone else has done the research I'm asking. I know that 2 different solutions working differently could still each work to the same end. I've used Perma wash, but I've have started thinking much more about what I'm doing lately. Therefore, I ask those with much more experience.
Having had issues with the well water and film, I approach printing on fiber with trepidation. I haven't noticed anything awry with RC paper, but will it show with fiber? I can't really wash with distilled water - it'll end up costing more than the chemicals. Is try it and see the only answer?