Sawyer Squeeze restoration?

I bought a Sawyer Squeeze a bit over a year ago, used it on a few trips and was happy with the flow rate etc. I backwashed it each trip but didn't run disinfectant through it as I thought that would taste awful. (Someone later suggested Milton anti-bacterial solution which is used for babies' bottles.) I ended up not using the Squeeze for about 9 months and when I tried it again the flow rate was almost non-existent.
Has anyone had this problem and found a way to rejuvenate it i.e. restore the flow rate?
Has anyone had this problem and found a way to rejuvenate it i.e. restore the flow rate?