Yes seuthe and lgb/massoth. Especially for a single loco. A bottle should last a very long time.
However…….for those that use the smoke regularly, and plentifully, i have made a fluid from half bbq lighter fluid and half tiki torch fuel. It doesn’t harm the smoker.
I have used this for decades, on literally 100 of my locos, lgb, bachmann. Regular seuthes and massoth pulsed. It smokes well, but is strongly ‘scented’. Im certain it is, at best , somewhat toxic (have no idea compared to the blue massoth/lgb fluid). I use it primarily outside. Inside……as i wrote , its epic….