Given how easy it is to enable RBF on a transaction, there really shouldn't ever be a reason to require a transaction accelerator anymore. Just opt in to RBF with every transaction you make, and you can replace it later with a higher fee if it gets stuck. This will work out much cheaper than paying any transaction accelerator service, not to mention quicker and easier as well. Even using CPFP will probably be much cheaper than paying for a transaction accelerator.

Is your transaction opted in to RBF, or does it produce a change output? If so, use RBF/CPFP instead.