Every method is the best in it own way. However, you can try to wash your material until certain conductivity is reached and to find the optimal procedure (washing and conductivity) for you application.
Our actual purpose is to obtain Cellulose=Cellophane film AND, naturally, by using the simplest way. It's obvious that there are very few simple ways in polymer syntheses... YET we are trying to find such.
It really happened that by somehow (?) I overlooked the Article : "Brief overview on cellulose dissolution/regeneration interactions and mechanisms" and am very grateful to you for sending a link to it.
Also I studied the list of your publications and found your papers on Keratin structure. Since recently the laboratory I am working in cooperation with - started to use keratin as an additive. Although I am sure (and proved it) that keratin can not react with the matrices they use - your paper is very useful.