Most kittens immediately take to using a litter box and don’t need any training to do so. But what about those who don’t get it right away?
Not to be too alarmist about it, Jan, but you must immediately stop using Pine Sol around the cats. Most people just don't realize how EXTREMELY dangerous it is to them. Lysol is equally dangerous. Both products have names that end in "sol" because they contain phenols that can kill cats. Kittens are especially at risk because of their small size.
The best product to use to clean litter box messes is an enzymatic cleaner. Use anything else and the cats will still be able to smell their pee and poop quite easily. Even through heavily scented cleaners. We’ve used the Simple Solution product pictured below, but most any reputable fragrance free enzymatic cleaner will work.
That said, there are several ways to help the kittens find their way. First, clean up after them with the enzymatic cleaner I mentioned above. Then place the litter box where they want to go anyway. Make sure it's in a location that doesn't have any surprising sounds (like an air conditioner suddenly turning on) and where there isn't a lot of traffic.
There are several things to try in order to help them want to use the litter box:
There should be several boxes for the little ones to use. Even at their young age, some will not use a box with more than a few "deposits".
The box should have low enough sides to allow them to get in and out easily.
Some high-sided or covered boxes can scare cats and make them feel trapped. Automated and covered boxes are generally not a good idea for any cats, but especially for kittens.
Make sure the litter box is as far as it can be from where the kittens eat.
You may want to try some different types of litter. Litter with larger pieces (we like Purina's Yesterday's News) are great for kittens because the kittens can't eat it, but some kittens don't like the large pieces. Clumping litter can be hazardous to kittens if ingested. Plain clay litter is fine if they won't accept the chunky stuff.
Be positive! Never scold a kitten for making a litter box mistake. Praise them and treat them if they so much as go near the litter box. Help them to see that the litter box is a great place to be! Some kittens we've worked with have learned to love it a bit too much. We have one who still comes running to watch us scoop. :) It can take time for some individuals to learn their way, especially if their mother isn't around. It's up to you to be patient with them and help them learn.
As a last resort, you can use a litter box attractant. These products entice the little ones with scent, but it really should be a last resort. Give them a chance to learn without this crutch first, or they may grow to expect it.
Thank you for looking after these babies! With your help, I'm sure they'll be using the litter box in no time!