A clear case where disputing may work
How old is the debt? Since it was sold 5 times it must be close to 7 years. If that is the case simply let it age off your report.
What type of debt it is? If the debt is a single entry item like unpaid medical, cellular or utility bill then it may be worth to try disputing it. If the debt is a regularly reported item like defaulted credit card debt, even if you succeed in getting the collection account off your report it won’t improve your score because the original creditor’s charge-off which is the serious negative will remain on your report.
I normally would not advise this, but if the debt is a single item you might want to just dispute the collection account with the credit bureaus. The collection agency probably won’t respond (since it’s gone out of business) and the item will be removed … at least till some other collection agency buys up the debt or 7 yrs have passed and it falls off.