can't swim crawl through 1x1 gap due to swim floating fix!

example:

https://youtu.be/EaTKwcaWCIQ

Time:1:17

It worked at the the time I recorded the video

1. dig a 3x3x2 hole in the ground
2. at the right bottom dig a 1x1x1 hole straight for 3 blocks
3. put water on the block next to the 3 block long hole 
4. break the front middle block on the ground