swim has never had much luck with a successful LC, however a few things learned would be:

too large of chunks of myc in the LC could clog the syringe

the more surface area exposed by healthy myc in the LC could result in better, or quicker colonization times

both of these could be remedied by putting a decent sized washed glass shard into your LC before pasteurization. give it a nice swirl when one notices the myc getting to large, and it will be cut up.

hope this helps