xXx wrote:
Hello
I have run out of end grain preservative and cannot get any from
anywhere...even online is proving difficult to find in stock.

So my question is- Can I just use the decking stain/sealant I have as
a substitute?
Or does anyone have a link to a site I can get it from...

regards
ST

Waste of time anyway IME. If you want to stop rot, the only way is to
ensure that there is sufficient ventilation round it so that it gets a
chance to dry out.
If this isn't possible, try rubbing a candle over the end grain.
Paraffin wax is an excellent waterproofer and, because most of the
moisture going in and out of wood travels this way, it should prolong
the life of the boards. Surprisingly little water penetrates the faces,
however wet they look.