I use Canadian nightcrawlers in both of my house plants. I have a poinsettia and a pothos. I have a very standard plastic container for the poinsettia which came with it when bought. It has two nightcrawlers in it. All I use in this plant are the original leaves that fell of the plant, eggshells that I ran a little water over after use, and used coffee grounds. Coffee grounds I spread around the pot to keep in moisture. Only use eggshells if you are really looking forward to reproduction. I have quite a few of tiny worms embedded in the soil. At the very beginning I did cut tiny pieces of banana peels into the soil and mixed it around. Since then I've added nothing. My leaves are thriving wonderfully that are come in and it's winter at that. On top of that, it still hasn't lost all of it's original leaves. Still hanging on to about 5, lol. Far as my pothos go, it has only 3 nightcrawlers in it. It's in a 10 gallon plastic container. Which leaves these nightcrawlers a lot of room to burrow. Haven't seen them since I put them in. To say the least since doing that I have not did any of things I did with the poinsettia. As I am seeing what works best for each one. My pothos is growing fabulous. It has become longer, healthier, fuller, and plenty of new leaves sprouting all the time. One more thing, when I received the poinsettia it was barely making it. To each it's own. Nightcrawlers would be the best route to take. They do not destroy roots only things that are decaying.