Tried the tablets some years ago. OK but no improvement on the fluids and if the sachet gets the slightest tear or pinhole in the outer, the tablet takes in atmospheric moisture and degenerates int o a gooy mess.
More recently I've changed to Fenwicks Top and Tail which uses same fluid for holding tank and flush, is green and stains and smells much less and seems to retain it's detergent action longer than the others.
Halfords sometimes have a good deal, s especially if you buy 6 at a time as we do for Continental use.
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