Paid accelerator charges too excessively and not advisable, but if you meant ViaBTC free accelerator, Dantevos85 should know that only transaction with feerate of 10 sat/byte and above can be accelerated, any amount in fee lower than that can not.
It is not only a question of fee rate, but also perfect timing, considering that it can be successfully done only every full hour, and from my personal experience, even choosing a browser can play a role. Even if the transaction is successfully added, sometimes it is necessary to wait for several hours for Via to find the block, so all this should be taken into account.
