I have a fireplace where normally I burn firewood. Now, because it is better, I am using pellets. For this, I only had to put an iron mesh at the bottom to prevent the pellets fall to the ash tray too soon. Well, it works very well, at last I am free from the gas supplier, the only source of energy I depend upon is electricity, my car is electric too and made in Portugal.
This allows me to use the cheap nightly electricity to heat water and to charge the batteries of the car. But today, and that is the reason of this post, before I through away the ash of the fireplace, I decided to wash it in a basin. Then I measured the pH of the washing water and it was above 12. I filtered the water with coffee filter. Then I thought this water could serve as a basic medium to develop photo film or paper. Indeed it worked! I have tested with coffee+vitC added to that water and keeping the pH hight enough, around 11.
So, if you can't find washing soda at your drugstore, try this method with wood ashes from your fireplace. Important here is to keep the pH high enough, I don't know how concentrated the solution was and by now, I used a 1:1 solution of coffee and vit C dropped in the ash washing water and it turned a piece of photo paper black in some 10 minutes.
The next I am going to shoot and develop with ash, coffee and vit C.