As a newbie when making something, I start with the end in mind. For example, you want to cook chicken in a rice cooker. I will google and see the results. I got no results for chicken thighs by themselves. (Lots of recipes for them made with rice though!) So I backed off and used a search for chicken only in a rice cooker. Whole chickens in rice cookers came up. A lot of recipes for whole chickens, in fact!
So...I looked at them. Most are likely not what you will want as it seems that you want to make just chicken for other purposes and don't want to add various flavors. (I am making a lot of assumptions, which I normally try to not do, but I am trying to help!)
I saw this recipe here. This recipe has a lot of things you might not want to add, but I look for what will likely be needed. (Liquids) I would stick to the total amount of liquid used. The person who made this dish seasons and preps the chicken. You could use your own seasonings, but follow the prep because she likely knows what she is doing.
She adds aromatics and spices, which you can add or omit. I do think some onion and celery might make for good chicken to be used for generic purposes as well as pepper, salt, etc. She marinades the chicken which you may decide not to do. She sets the chicken on aromatics and then describes how to test it for done-ness.
It is likely she uses the whole chicken because there won't be an area overly dense and cooking is going to be more uniform.
There were a lot of recipe ideas for cooking a simple whole chicken in a rice cooker without rice, including several in very simple cookers. If you try it, I hope you tell us how it turned out.
