I was just going to go with the crosswise brick exercise and be done with it but then I came across Hermann during my research.
I saw that exact same thing (sticking point smashers) when I was looking around. At first I thought it was an e-book or some money scam, lol, until I read more and found out what it was.
You know, your bag idea will work with a barbell as well. Just strap it to the ends with a brocolli elastic (possibly the most versatile piece of vegetable equipment, lol) or something similar. The bag will deform around the bar and stay in place with the elastic. Provided you get most of the air out when you seal it. A medium sized Ziploc freezer bag would work well.
You want to know a really dirty trick for the brick lift? If you use a hollow brick (a brick with holes in it) most of the time you can fit one of those old school camera film containers in the hole. You know, the little black plastic canisters that film came in. You can fill that with shot, bb's or what have you and stack multiple canisters in the holes. They may be taller than a brick but it will insert into the bottom of the next brick. The lids may not fit through but you don't need them anyway.