I use the method described but feel a couple of things need to be considered.
First ,it was noted on the video that there was also some rock taken from a cycled tank along with the sponge filter squeezings and it was also noted that placing the entire filter from the cycled tank into the new tank might also be beneficial and I would agree.
I have sponge filters running in three tanks and when setting up a new tank, I simply move the sponge from the cycled tank to the new one. Squeezings will work but in my view would be much better to squeeze the sponge filter into the filter compartment on the new tank as this area is where the bacteria can best develop.
Should also be noted that bacteria develops in direct proportion to the food available (fish waste). So if you take a sponge filter from a tank holding three or four fish, and squeeze the filter and bacteria therein into a tank holding many fish,,, there will possibly not be enough bacteria to process the waste of the many fish as the bacteria will only have developed in proportion to the numbers of fish in the tank it was taken from.
Always best to stock slowly for this reason. Too many fish or too large of fish added too quickly and bacteria will not be sufficient to prevent possible ammonia spike.
Would not use this method and expect to stock the tank to capacity overnight without expecting possible lethal levels of ammonia until the bacteria has had a chance to catch up with the load. Other than this, I feel it is a very good way to jump start the maturing process and it can decrease the time it takes for tank to mature or (cycle) considerably.
Might also note that bacteria develops a bit more quickly in water with pH above 7.0 and develops MUCH more slowly in soft acidic water .