Not too much information about this subject, but still enough to make a separate mention.
“De Nederlandse Vegetariërsbond” (‘the Dutch union of vegetarians’) was founded as early as 1894. According to Wikipedia, the initiative came from A. Verschoor from Rotterdam. What Wikipedia doesn’t mention is that at the founding meeting several Theosophists were present. With P.C. Meuleman-Van Ginkel we are already in the Van Ginkel family of Henri van Ginkel who would initiate Farwerck into co-Masonry in 1911. Meuleman was also involved in the early days of Dutch Theosophy.
Most likely through his Theosophical contacts, Farwerck joined the union late 1918 as we can see in the periodical of the union that can be found online. Apparently Farwerck was not as active in this union as he was in other groups that he found, because the only other mention in the named periodical is from early 1922 when he resigned. Also this issue can be found online.