I’m not an expert , but I would have thought the answer was relatively easy .
You identify your customers , and where they will buy .
So I am guessing two customer groups — motorhomes/freedom campers , and toilet hire firms .
So compile up a database of toilet hire firms , and either courier out a 4 litre bottle , with marketing and a letter . Or get their individual e-mail addresses , send an email to each place/branch , outline the benefits , and have a reply ‘coupon’ , where you send a 4 litre ( or whatever ) sample . The second option means they actually read the info , and opt in , so they have some ownership . Just sending a sample will mean it not only costs you more , but at least some places will just go ‘oh , it’s a freebie’ , use it and not monitor or follow up , and continue with present suppliers .
The email ‘opt-in’ also means that after ‘stage 1’ , you not only follow up with those interested , but also make others aware of what is on offer . Slower , but more effective , and easier to monitor .
The second group that I call motorhomers , you do similar — make a database of RV suppliers , Associations , and possibly caravan parks and the like . Offer them an initial 50% discount , maybe 12 1 litre bottles you say retail at $9.95 or whatever , normally wholesale at $6 plus GST each ( $6.90 ) , the next 3 months are $3 plus GST . This may be below cost ( doesn’t overly matter — you are getting product out — better than making nothing on no sales ) but it gets your product , name and website out there .
A website and a facebook page ( I am old-school ) is great — a bit like the Yellow Pages ads of old . You need to do more , get brand recognition , then people will contact you when they see an ad on-line ( plus done right , it helps your SEO rankings ) .
I hope that advice isn’t out of line