Want to be traditional get a stone lock.
Using bricks for tai chi empty hand form is a monumental bullshit halfway house training method that ends up with the worst of both worlds. straight up load of crap. Bullshit that completely misses the point.
Used to work with what were called wood locks, and brass rings, which for those on a budget can be made from car springs cut, welded together forming a ring make sure to grind down the rough edges left by the welding befor use. No explanation necessary for those who skip this step, they will know.
Used to use a weight bar for an iron staff to train with.
Funny story: some were watching me training with my staff, not realizing that it was a iron bar.
One guy asked if they could try it.
I tossed it to him, the look on his face
as he caught and dropped it was very funny.
As you've mentioned there are specific ways to use each, each designed to develop different areas.
In my own experimentation used to use 1lb lead fishing weights,
not a good idea "lead" being the first part,
young and dumb didn't know anything about lead.
The other parts as you've mentioned I found it tended to throw off the mechanics of
effective punching in supporting the weight.
Another point not mentioned is "intent"
If one is holding onto a weight ones intent
is focused on holding the weight, not going through the fist.
of course as in all things, some may feel its a good idea, I would not based my own findings.
Traditional CMA training.
There is a saying "eating bitter"
I onced asked my teachers grand son about how does one get better in taiji.
he said "the more pain you can endure, the deeper level of skill you can achieve"
"Traditional"
can mean different things at different times in CMA development history.
There are clear points where the focused changed becoming the new tradition.
In the taiji world, the early masters were known for their usage of the art though
martial engagements common for the time. There are clear time points were one can read about the exploits of the old masters,
but can not find any corresponding exploits of the modern masters.
At a later point up to this time, IMO the focus changed allowing a training tool "push hands"
to come to the forefront as one of the main ways to test and observe taiji skill.
Oddly enough those who's training reflect the "Traditional" masters before this change
might not be considered as using taiji. While those who's training after this time might be
but have not shown this skill outside of their own specific format "push hands"
One has to understand their own training focus.
I would say the focus on "health" was
secondary to usage "fighting" which later changed to be more focused on "health"
not necessarily good for usage "fighting"