There's only 4 periods in one day. So, in the first day, you can only use the cleaner 4 times.
But don't worry, you have to use the cleaner 5 times in the first part of the game, i.e. days 1 to 5.
The teacher appears in the 1st time, but it's in the school (normal
). When she "really" appears in day 6, it's in your house, so that you can control her.