No.
Even in cases where statute "protects" people against liability for injury, this is not true.
An example:
A stable offers trail rides. Statute says that people who voluntarily participate in activities that are inherently dangerous (not the exact wording, but I'm not looking it up and it's close enough) are liable for any injuries they suffer, and the provider of the service is not. In addition to this statute that protects the provider of the service, the stable owners ALSO have everyone who participates in a trail ride sign a hold harmless agreement, stating that they understand that horses are big, dangerous creatures, and they're ok with that, and if they get hurt they understand that it's no one's fault and the farm is not responsible.
Someone gets hurt. If they can prove negligence? They can win a law suit. The statute AND the hold harmless only protect the owners of the farm and the farm itself from liability if there is no negligence at all.
And so, the stable ALSO carries liability insurance which will cover any associated costs due to injury/negligence.
There is no way that you can install something like this in your back yard and let other people use it, and be assured that you'd be protected from liability just because they signed a waiver.