Well if I'm honest as yet I haven't tackled it

I am going to get some sand and see how that works out for now.
Any ideas i had of stone or pebble or hard material; I wont try until its actually dry as mud will swallow such material in a very short time, like in gate ways etc.
Still thinking on the bark idea if I'm honest

Sand first then will see how it goes, sorry peep's been so busy sorting for the new pigs of late.