Bussing leftover broths

Unlike other restaurant foods, pho usually has large amount of leftover broth in the bowls when the customers finish their meals and leave the restaurant. Between the 2 extremes of

1. Bussing the tables using push carts in the dining room like many old school Viet restaurants do (my least favorite method), and
2. Bussing by carrying bowls individually (not my favorite either)

I'm just wondering if there are other more acceptable bussing methods for pho. From my perspective, I think the requirements should include (not in order of priority or importance):

• Safe
• Acceptably fast
• Convenient and not costing too much
• Clean and sanitary
• Good customer experience (meaning it looks acceptable to the customers)

Ideas and/or discussions on this is appreciated.