Purchased a bag and used for the first time last night with Blackcurrant wine. Worked fine and the fruit washed out of the bag with minimum fuss. It was the type that sits in a 1 gallon fermentation vessel and can be stretched over the lid area to make things easy.
On a recent Raspberry and mixed berry wine I used a collander, however when I transfered to a demijohn for storage, I noticed a lot of fine bits at the bottom.
I will see how this goes or look into other staining methods.
Thanks for the replies above.