Industrial rubber gloves are a cheap and handy addition for any all-grain brewer but can be an extra God-send for the BIABrewer without a rope and pulley. Simply lift the bag slowly and twirl it until tight letting the sweet liquor/wort drain into the kettle. Now, just dump the bag. A twisted bag for a standard batch will weigh at this stage around 8kgs (17.6lbs) at most.
Like batch-sparging, you can spend all day waiting for the grain bed to yield every last drop. At some stage, you have to stop though
. A good guide is to hang the bag from something like a door knob over a food-grade bucket and leave it there while the brew comes to the boil. This will give you an extra litre/pint or so.Make sure you keep it simple and easy. Spending ten minutes twisting, squeezing and draining a bag is the equivalent to a batch-sparger tilting their mash tun and draining the results into their kettle for the duration of the boil. It will give you a fraction more beer but also more trub and is something easily compensated for by a fraction more grain.
Aim in the long run though to have a rope and pulley system. It just makes things more comfortable.
If you have questions regarding this topic, feel free to ask them here.