Method #4 "feeding the fish" is incorrect in the difficulty rating, and not explained very well. It seems the author lists it for No.2 without any prior practical experience.
Its difficulty is at least 3/10, as one has to maintain a slight forward body tilt while simultaneously applying a very gentle breast-stroke swimming moves during the ...ahem... more difficult moments. This calls for some coordination and agility.
If this is not done, one may end up with short or more-often - prolonged - skin contact with the ...product, the product being lighter than water, and having the tendency to ascend to surface straight up.
No need to ask me how I know this.