Apparently, methylated spirits / methyl alcohol / ethanol is very hard to find in Russia, so I am considering to bring mine on the train. According to this page (not an official source), it is prohibited to bring Toxic and explosive materials into Russia. Would that include camping fuel? It's not entirely explosive but it's certainly toxic! Can I bring a couple of liter with me on the train into Russia?
According to "Goods, prohibited or limited for transfer via the customs border of the Eurasian Economic Union" (where Russia is a member state),
List of the goods for the personal usage, prohibited to import into the customs territory of the Eurasian Economic Union (hereinafter - the Union) and (or) export from the territory of the Union
3.4 poisonous substances, which are not the precursors of the narcotic drugs and psychotropic substances
Edit: If you would like to bring ethanol to Russia, you are allowed to do so (up to 5 liters). However, according to Decision of the Council of the Eurasian Economic Commission dated 20.12.2017 N 107 (as amended on 01.11.2018) "On certain issues related to the goods for the personal use" (only in Russian), you need to pay 22 EUR for each liter.