Yup, I know someone who had COVID and it completely broke/made their sense of smell of certain foods disappear, and later it was "repaired" right away after taking a single dose of LSD. That person had no idea of this, and found other anecdotes posted online, so it wasn't a placebo. The way how I imagined this worked is that COVID weakened/malformed some neural connections responsible for remembering these smells but LSD fired these temporarily. So I recommended to that person to regularly pay attention to these smells so the connection doesn't fade over time. Few months later it was still in full effect - I know it's highly anecdotal and not very scientific reasoning but still it was a nice unexpected side effect

Qualia Computing is fun but I'd caution against citing it as a serious academic source, since it mostly consists of abstract conjecture and untested hypotheses.

But while I'm here, let's explore fun. It could be that recovery from anosmia works like, say, nerve pain from spinal cord injury. It seems that the false feelings (burning, electric shocks, allodynia etc.) experienced by paraplegics are the result of neurons sending very different input than the brain has learned to process. Obviously LSD won't help you walk again, but e.g. exposure therapy for allodynia seems to work, probably through neuroplasticity.

Qualia Computing I'll agree contains a lot of conjecture, but I wouldn't call it untested. If anything, they tend to test it as often as they can get their hands on it!