I have a poo bag dispenser attached to Kaiser's lead so they are always with him

In the garden I just stuff a load of asda bags in my pocket and go poo picking.
One thing I'm not sure on though is how on earth are you meant to pick up liquid poo?

Had an unfortunate instance on Sunday, up on the dales, Kaiser ran off the foot path, crouched down and it was liquid, I didn't know what to do

I'd left my bags in the car (borrowed a retractable lead for the walk) and the ones my aunty had brought with her had holes in so I'm ashamed to say I had to leave it there :but even if I'd had my own bags, how do you pick up liquid?!