Should you put all work experience on your resume, even if it  didn't work out?

This is a highly personal decision that needs to be made. However, if you indeed worked for a company and they had you on their payroll (withholding taxes, issuing tax statements, etc) and they can confirm that you've worked for them for a certain period of time, it's best to disclose this - otherwise you will have numerous employment gaps which won't look good. There is always a reason for parting ways with a company: some amicable, others not so much. Still, if you were on a trial period and you were not hired, chances are that the need for another employee went away - or if you had automated some process (being a good employee that you are), the position may have been completely eliminated. This can be presented as a project and not a full-time employment. You can explain this decision (to take on a project) as a temporary measure while you were looking for a full-time employment, however you might not have wanted for your skills to deteriorate, so in order to keep those skills current, you may have picked up a some projects along the way to avoid gaps in the employment. If this is presented properly and with a proper proof/conviction, it will only be a plus for you as a person since it shows high work ethic and determination.

In general, the purpose of a resume is to get an interview. The questions you have to as yourself is would the practical experience you gained help you get that job and how long was the job in question. If the answer is that you gained a lot of experience and it was a long term project, feel free to put it down. On the other hand if you didn't do much and it was a short term project, you might want to leave it off unless it will put you in a position where you have a really big gap. That aside, most hiring managers should know if you were a contractor that your time with that organization is highly variable. If they don't understand that, then you have a much bigger problem since they don't understand that being a contractor implies that you work on relatively short-ish time assignments (typically up to 18 months).