n80,
You were lucky if you heard and used that spray only now. Just so you know, it does not last forever. More spray may be needed over time.
If Toshiba has outputs for two speaker pairs, I would buy two sets of speakers. Some that you are looking for now anyway and a pair of weather-resistant speakers to put outside permanently and forget about them. No more "bring them out". They are usually not obscenely expensive.
Something like this..... https://www.crutchfield.com/p_107ATR4B/Polk-Audio-Atrium4-Black.html?awkw=75619821025&awat=pla&a...