Breh you can definitley use them for straight punching, just do it. I like it because it's unusual shape forces you to punch differently (which is good for fighting) and forces you to work on angles and adjust trajectory. Create combos that involve straight punches, hooks and uppercuts, then ending it with ducking under the bag. Most people work on 3 punch combos, try 5 punch combos, 3 punches, duck under the bag come up on the other side and finish with 2 punches. You want stamina, do 3 rounds of that, you're not going to be able to finish 3 rounds at first but when you get tired, don't stop just do it slow until you build up. You can also use it for infighting. Lean on it and throw punches, it'll help you when you're tired and can't throw anymore.
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Ski you weren't joking I started working the bag like this, it's good shyt. Will try to get a video later. But it's a fun way to throw awkward combos (hook uppercut) and def work on inside fighting. I'd recommend a wrecking ball to anyone.