Is your husband taking anything by mouth right now? The presence of "slight aspiration" on MBS shouldn't fully preclude him from eating small amounts especially if he hasn't had a recent history of respiratory infections/pneumonia. Check with your SLP to see if you can be doing trials of safer food/fluids at home. If it's "safer" for him to swallow small amounts of apple sauce for example, with a posture (like a chin tuck) that increases the protection of the airway then your SLP may feel comfortable training you both to know what to look for so that you know if and when you should stop with the limited trials to minimize aspiration risk. The more he can use the muscles of the swallow the sooner he's likely to see progress. Keep at it - I consider "slight" aspiration not to be too bad of a thing - it may be managed and/or improved!