Providing receipts are kept for all expenditure then HMRC can grant a dispensation even if there is no third party checking of the claims - providing the company is a one man bad company as you describe.
http://www.hmrc.gov.uk/paye/exb/schemes/dispensation.htm
If it is not possible for you to operate an independent system for checking and authorising expenses claims - for example, because you are the sole director of your company and you have no other employees - you will only be able to obtain a dispensation if you:
ensure all expenses claims are supported by receipts for the expenditure
demonstrate that the claim relates to expenditure that can be covered by a dispensation - your receipts may be sufficient for this purpose.