No company solicited this review, and I purchased all tested items.
The Sawyer Squeeze, Sawyer Mini, and Sawyer Micro filters are among the most popular water filters used by backpackers. After a lot of use, these filters must be “backflushed” (or “backwashed”), which means pushing clean water backwards through the filter to flush out dirt and grime that clogs the filter. Sawyer recommends backflushing when the flow rate diminishes, before long-term storage, and before using the filter after storage. Most long-distance backpackers backflush at least once a week.
Sawyer filters come with a 31-gram/1.1-oz. syringe used to backflush the filter. Since long-distance backpackers are concerned with weight, I wanted to see if there is a lighter-weight alternative to carrying the Sawyer syringe for occasional backflush use.

Left to right: Sawyer Squeeze, Sawyer Mini, Sawyer Micro
Common Backflush Devices

Sawyer 50 ml syringe (top), Sawyer coupling device (lower left), and 0.7-liter Smartwater bottle flip-top nozzle (lower right)
The Experiment
I tested the flow rate of backflushing the Sawyer Squeeze, Sawyer Mini, and Sawyer Micro using three different methods:
1. Sawyer Syringe (31 grams)
2. Sawyer coupler (6 grams)
3. Flip-top nozzle from a 0.7-liter Smartwater bottle (6 grams)
The photos below demonstrate how to use each device to backflush. Note that you cannot use the Sawyer coupler to backflush the Sawyer Mini.
How to Backflush the Sawyer Filter

Syringe backflush of original Sawyer Squeeze. The syringe can also be used to backflush the Sawyer Mini and the Sawyer Micro.

Coupler backflush of Sawyer Micro. (The coupler’s threads match the Smartwater Bottle.) The coupler also works with the original Sawyer, but not with the Sawyer Mini.

Smartwater bottle nozzle backflush of a Sawyer Mini. The nozzle may also be used to backflush the original Sawyer Squeeze and the Sawyer Micro.
Lightweight options work best

Backflush flow rate in Liters per Minute. The lightweight Sawyer coupler and the Smartwater bottle nozzle outperform the Sawyer syringe in all cases.
The Results
Our tests demonstrate that backflushing with the Sawyer coupler or the Smartwater bottle nozzle is better in all cases than using the Sawyer syringe. The best backflush flow rate was observed with the Sawyer coupler + original Sawyer Squeeze combination.
You save 25 grams / 0.9 oz. weight and have better results if you use the Sawyer coupler or a Smartwater Bottle nozzle to backflush your Sawyer filter.
Bottom Line, TL;DR
Read Parts 1, 2, and 4 of this Sawyer review series:
Sawyer + Backpacking Part 1: Review of the Sawyer Micro Squeeze
Sawyer + Backpacking Part 2: Sawyer Squeeze and Sawyer Micro Squeeze Flow Rate
Sawyer + Backpacking Part 4: Sawyer Mini, Micro and Squeeze Compared