Never use "self-watering" pots. They are a fraudulent gimmick.

Instead, I love terra cotta plant pots. Inside the larger saucer, set a small saucer upside down. This creates a moat for excess water and provides valuable humidity.

Plants should never sit in water. This rots the roots.

At age 17, I started this Christmas cactus from two starts in Michigan. Your Christmas cactus is likely dried up in its heart. This will cause it to die.

Fill the tub or a large bucket with lukewarm water, deep enough to go over the top of the pot. Submerge the pot. Keep adding water as the plant absorbs liquid. The water level should stay above the soil level. At first it will bubble like crazy; this is air escaping. Soak the plant and pot for 3-4 hours. Drain thoroughly.

In May 2018, I took cuttings, and grew two new plants. Gave Christmas cactus plants to my daughter and a friend.

Caring for your Christmas Cactus and How to Make It Bloom

Your Christmas Cactus is a succulent. It stores water in its leaves. These plants are neglectable. That said, succulents have specific requirements:

1. Bright, indirect light. A north-facing window is best. NO direct sun. Direct sunlight burns the leaves.

2. Water thoroughly until water runs out the bottom of the pot. Don’t let the plant sit in water; this causes root rot. Let the soil become dry before watering again.

3. To make the plant bloom, withhold water and extra light during the first 3-4 weeks of October. “The plant thinks it’s dying and throws out flowers and seeds to propagate the species,” a botanist explained.

4. When buds form, fertilize with ½ strength Miracle Grow to plump up the flower buds. In the Spring, fertilize once in April (½ strength Miracle Grow) and once in June to encourage new growth.

5. During the winter, succulents grow dormant. They like a bright, cool spot (without freezing). Don’t water as often when the plant is dormant. If the leaves shrivel, the plant needs water. Increase watering in the Spring when new growth forms.

6. When roots get crowded, re-pot in the Spring. Use a mixture of ¼ sharp sand (not beach sand that compresses) and ¾ potting soil. Put a layer of broken pot shards in the bottom of the pot to improve drainage. Keep the soil mixture on the dry side. Succulent roots are fragile and easily damaged. Trickle soil lightly around the roots; then firm in the plant. During the first week, lightly mist the soil around the roots with water. After a week, you can begin watering as usual.

In the Brazilian Rainforest, Christmas Cactus grow high underneath the canopy in tree crotches. They like tight feet. I haven’t repotted my big Christmas Cactus in 25 years. Repotting a huge plant is a major job that takes two people.

A pot-bound plant can dry out in its heart. This ultimately kills the plant. To fix this, soak the plant in a tub or bucket, with water over the pot rim. Let the plant soak for several hours, until bubbling completely stops. Drain thoroughly.

Another trick is to put ice cubes on the soil around the plant. This waters it slowly as ice melts. Ice cubes also help hanging pots that easily dry out in the heat.

I know @literatehiker has one that she has cared for that blooms beautifully each year...maybe she will see your post and help...I tend to overwater...and I just don't have the patience anymore for indoor plants...

I have several of those kind of pots...obviously, they did not work for me...I had them for African violets...all dead now...