I would hesitate to recommend using a shaver socket with an isolating transformer to charge a toothbrush, or even a rechargable shaver. Many seem to be specified to power a mains shaver for as long as it takes to shave, that's quite a short duty cycle. They don't seem to cope well with prolonged use recharging batteries.
The problem is only a socket with an isolating transformer is deemed suitable for use in a bathroom...... Rock and hard place......
TBH the charging current of a toothbrush is minimal, and I have never known an isolated shaver socket to fail due to this.
Not shoddy - just that these are shaver sockets, designed for shavers.However rather than blindly defending the manuacturer for making shoddy goods
Shaver sockets should be banned, since there are no shavers which can fit into them - they are all the rechargeable type now.