In order to prove that claim, an ancient manuscript of Mark's gospel with what we call chapter 10 in it, and having verses additional to copies written around the same time, would have to be presented. It is therefore not surprising that you can not include in your question any evidence supporting the claim. The answer given here, with a copy of the letter supposed to be from Clement and rejecting this 'Secret Mark', has links to aid your search, whilst discounting the claim.
This supplementary answer is just to deal with the idea that, "It is strange in 10,46 Jesus came to Jericho, and immediately he leaves it". No, there's nothing strange about that at all, as previous verses state that Jesus and the disciples were on their way to Jerusalem. Their destination was not Jericho; they merely had to pass through it on their way to Jerusalem. Besides, Matthew and Luke's gospel accounts provide more details.
Mark's account is brief, and to the point. So much so that he completely misses out the nativity, diving straight into John the Baptist's ministry when Jesus was a mature man. He leaves out many other details the other writers include. He wasn't doing a carbon copy of other accounts. It's almost as if he's tripping up over himself in his haste to get to Jesus' being in Jerusalem for that last time. Then Mark slows right down and dwells at length with that final part of Jesus' ministry.
Therefore, there's nothing strange about Mark giving no details about any stay in Jericho, only mentioning the healing of blind Bartimaeus on the way out of Jericho, as Jesus continues on to Jerusalem.