I have always in the past successfully washed capillary matting on a gentle cycle low temperature wash without detergent and have probably recommended this here too.
However, the latest batch I bought this spring seems to have some sort of paper backing, rather than textile. I have just spent half an hour cleaning some horrible sludge out of the washing machine and what was left of the matting is so thin that it would not do the job anymore.
Just to warn everybody that there seems to be some very inferior stuff around, even though it was bought from the same garden centre that I bought all my good stuff from and costs the same too. But that inferior type is one time use only, rather than the 3 or 4 years that I normally get out of capillary matting.
