Fill-to-order, label-per-household, closed-loop container swap

Mechanism

A central facility fills durable, standardised containers to order — one per destination, labelled per household or per delivery point. A carrier delivers full containers and collects the customer's empties on the same stop. Empties return to the facility to be cleaned, sanitised, refilled and relabelled. The customer never dispenses, measures, or carries a container to a shop — they swap a full unit for an empty one at their door.

How it addresses the five last-mile failure points

Hygiene/contamination: filling happens only when an order is placed, centrally, under controlled conditions. There is no pre-filled inventory ageing in a warehouse and no open dispensing at the doorstep — the contamination window is eliminated.
Dispensing mess: dispensing happens once, centrally, by machine. The doorstep interaction is a sealed-unit swap, so there is no taps-drip / overfill / measuring problem.
Reverse logistics: the empty is collected on the same trip that delivers the full one — the loop closes "for free" on a trip already being made.
Retail integration: bypassed entirely. There is no refill station, no variable-quantity scanning, no retail floor space.
Consumer friction: reduced to "leave the empty out, receive the full one." No container to remember, no shop trip, no behaviour change beyond a swap.

Operating profile and honest limits

The reverse-logistics cost is moved, not removed: the operator now runs central collection, sanitation and refill. This consumes water and energy and only beats single-use if containers cycle enough times — standardised, durable containers are essential, and bespoke per-brand bottles work against the economics.
This is a closed-loop design — it eliminates single-use packaging in the customer's hands, but "zero waste" should be stated honestly as a minimised, amortised operational footprint, not literally zero.
It needs a delivery-and-collection round to exist; it pairs naturally with batched/scheduled routing and with concentrate (lighter containers cycle more cheaply).

Evidence

The closed-loop "deliver full, collect empty, clean and refill" model is the modern milk-round; it has been implemented at scale with mixed results — see attached case studies.