No, not a stupid idea!
I realized last year that I had stopped using my French in any form and that it was decaying. I started listening to a French news podcast.
That was good for me, but then I also found a local French person who does French lessons, and now I go just shoot the shit for an hour every week with her. Like we just chat about whatever. It is immensely helpful and I am amazed at how it came back. From time to time I still find myself groping for a particular word, but I have regained a lot of the fluency I had before.
It sounds like my level of French might have been higher than your level of Spanish. I think your idea of getting a novel that you know well in Spanish is a good one, but you might risk just reciting what is happening in your head in English rather than focusing deriving meaning from the actual spoken Spanish. I have heard good things about Slow News - try
News in Slow Spanish.