Myself I find it rather odd if cleaners offer a gutter clearing service using a guttervac then they also should be prepared to use ladders if/when required and safe to do so too. Yes you can take risks using a normal ladder or minimise the risk especially working on your own by using the appropriate kit for the job in hand. The biggest killer is when a ladder moves suddenly caused by slippage and/or overreaching but the type of setup I use the ladder is not going to go anywhere if set properly.