We have an very old carpet here so it doesn't bother us much when there is an accident. But 5 out of 8 are completely trained and 2 are partially trained and will be completely trained soon. The only one who isn't trained is our newest addition Brownie. He has submissive urinating which makes it hard but I am confident with time and more training he will be completely trained too!!
We are trying to make sure they are all trained now because we will be moving soon and will have all new carpets. We are picking up a potty tent soon to see if that helps but I am happy that we have as many trained as we do!! We work really hard with them on their training and it so nice in the end to see all that hard work paid off!!
Toy dogs in general are hard to house train. They have such small bladders. Most of mine have been completely housebroken at 9 months, never had any broken at a younger age. It just takes alot of hard work, patience and time and persistance and it will all work out in the end!! Hang in there and try to stick with one routine, they need stability. Just keep doing the same thing over and over. It may seem like they aren't getting it but one day it will just click, trust me I have went through it several times. If you have any questions I will happy to answer them or if you need any advice just ask.